If your agency’s PDFs pass an automated accessibility checker, it’s tempting to call the job done. But a “pass” from a scanner and a “pass” from an actual Section 508 audit aren’t the same thing. Audits test how a document behaves for someone using a screen reader, not just whether tags exist in the file. Whether you’re a federal agency bound by Section 508, or a state or local government working toward ADA Title II, just passing a checker will not guarantee compliance.
The stakes are rising all over the country. The DOJ’s Title II deadline for state and local governments (population 50,000+) is now April 26, 2027, with smaller entities and special districts following in April 2028. Both rules point back to the same technical standard, WCAG 2.1 AA, so the PDFs that trip up a Section 508 audit, such as forms, reports, or public notices, are the exact same documents, with the exact same mistakes, that trip up a Title II review.
Mistake #1: Fake Headings
This is one of the most common issues in agency documents. Someone formats a section title in bold, bumps up the font size, and it looks exactly like a heading from a visual perspective. But without an actual heading tag behind it, that text is invisible to a screen reader’s navigation structure.
Screen reader users don’t scroll through a document top to bottom the way sighted users do. They jump between headings to scan a document’s structure and find what they need. A budget report, policy memo, or public notice full of “visual headings” with no real tags forces those users to read the entire document, which could be hundreds of pages, just to find the section they’re looking for.
Auditors check the tag tree itself, not the rendered appearance of the page. A quick way to self-check is to open the Tags panel in Adobe Acrobat and confirm that what looks like a heading is actually tagged H1, H2, etc.
Mistake #2: Decorative Images Left Untagged (or Mistagged as Content)
This mistake actually shows up in two opposite ways, and both are common in the same document.
First, agency seals, decorative dividers, background graphics, and watermarks are often left as regular tagged images instead of being marked as artifacts. A screen reader announces every one of these, cluttering the reading experience with noise that is not helpful or informational.
Second, and more damaging, are the meaningful images left with no alt text at all, or worse, alt text that technically exists but says nothing useful. A chart showing budget allocations across departments described only as “chart.jpg” or “image” passes an automated checker but tells a screen reader user nothing about the data.
The fix requires judgment, not just tagging. Decide whether an image is purely decorative or informational. Mark decorative images as artifacts, and create alt text that actually conveys the content and purpose for informative images.
Mistake #3: Form Fields with No Tooltips or Labels
Government agencies rely heavily on forms such as permit applications, benefit requests, FOIA submissions, and public comment forms. When form fields aren’t labeled, a screen reader announces something like “edit field, blank” with zero context about what information belongs there.
For someone filling out a public benefits application or a permit request, this isn’t a minor inconvenience. It can mean they simply can’t complete the form independently. Every field needs a clear, descriptive label or tooltip, and related fields (like a multi-part address, or birthdate versus today’s date) need labels specific enough to distinguish them from each other. Additionally, required formatting needs to be included such as MM/DD/YYYY, or (XXX)XXX-XXXX).
A close cousin of this problem is broken tab order, which includes form fields that are labeled correctly but navigate in an illogical sequence when a user tabs through the form, jumping from a name field to a signature line and back to a middle section.
Mistake #4: Reading Order That Doesn’t Match Visual Layout
Government reports and newsletters are frequently laid out in multiple columns, with sidebars, pull quotes, and callout boxes woven throughout. Visually, this layout makes sense. Read in the underlying tag order, it often doesn’t.
A screen reader might read straight across a two-column layout, jumping mid-sentence from column one to column two, or read a sidebar in the middle of an unrelated paragraph. The result is a document that’s technically tagged but practically incomprehensible when read aloud in sequence.
This is especially common in press releases, agency newsletters, and annual or budget reports, where design and layout tend to be more complex than a standard memo or policy document.
Mistake #5: Tables Without Header Tags
Budget line items, statistical reports, and comparison tables are everywhere in government documents, and they’re one of the most frequently mistagged elements. A table might have visible rows and columns, and might even have some underlying table structure, but if the header cells aren’t properly tagged and associated with their data cells, a screen reader can’t tell a user which column or row a given number belongs to.
This is also one of the areas where automated checkers are least reliable. A checker can confirm that a <Table> tag exists without verifying that headers are correctly identified or that merged cells are handled sensibly. That gap between structural presence and correct semantic use is exactly what a manual audit is meant to catch.
Mistake #6: Missing or Incorrect Document Language and Title Metadata
This one is easy to overlook because it doesn’t affect how the document looks or reads on the page, but it’s an explicit requirement. Auditors check for it every time.
Two things commonly go wrong. First, the document’s language attribute isn’t set, so assistive technology doesn’t know whether to read it in English, Spanish, or another language. Second, the document title in the file properties is left as a generic filename like “Doc4_final_v2.pdf” instead of a clear, descriptive title that shows up correctly in a browser tab or screen reader announcement.
Both are quick fixes, and both get flagged in nearly every audit that catches them.
Mistake #7: Treating the Automated Checker Score as the Finish Line
This last one isn’t a tagging mistake so much as a process mistake, and it’s the thread connecting everything above. Automated checkers like PAC 2024 or Adobe’s built-in Accessibility Checker are genuinely useful. They catch missing tags, untitled documents, and other structural issues quickly. But they can’t evaluate whether alt text is actually descriptive, whether reading order makes sense out loud, or whether a table’s headers are logically correct.
A document can pass every automated check and still fail badly for an actual screen reader user. That gap is exactly where most audit findings live.
How to Catch These Before an Audit Does
The good news is that all seven of these mistakes are catchable with a consistent internal process:
Run an automated check first, but treat it as a starting point, not a finish line.
Spot-check with an actual screen reader (NVDA, JAWS, or VoiceOver) on a sample of documents, especially forms and data-heavy reports.
Review the tag tree directly for headings, tables, and reading order rather than relying on visual appearance.
Standardize your process so tagging, alt text, and metadata are handled consistently across teams and document types, rather than varying by whoever happened to remediate the file.
Tools like Equidox’s HTML Preview let you see exactly how a screen reader will interpret a document before it’s published, which makes it much easier to catch reading order and tagging issues during remediation instead of after an audit finds them.
The Bottom Line
Section 508 audits are becoming more common, and agencies working through Title II compliance deadlines also face increased scrutiny.
The mistakes above are the ones that show up most consistently. It’s not because they’re hard to fix, but because they’re easy to miss when a document has some tags in place. Building a habit of manual review alongside automated scanning is the difference between a document that passes a checker and one that actually works for the people who need it.
Want a second set of eyes on your PDF backlog before your next audit? Talk to an Equidox accessibility expert or check out our PDF Accessibility Checklist to see how your current documents measure up.
Nina Overdorff
Nina comes to Equidox with years of sales and marketing experience from a variety of industries and holds a BS in Language Arts Education. Nina has a passion for words, storytelling, and information, which she believes everyone should have access to regardless of ability. After spending time as a teacher with a blind student, she became much more aware of the limitations and abilities of web accessibility, and how essential it is to those experiencing disabilities. “Being able to access information equally ensures that everyone has an equal opportunity for education, employment, and success in life.”
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